铈基氧化物催化剂用于氨选择性催化还原氮氧化物

摘要本文采用均匀沉淀法合成了一系列Mn-Ce催化剂和Mn-Ce-W催化剂，并对其进行活性测试，选出NH3-SCR活性最高的两种催化剂:Mn3CeOx和Mn3CeW0。3Ox催化剂。之后对两种催化剂进行了X射线衍射、程序升温脱附、单独氧化反应、瞬态反应和原位傅里叶红外漫反射等表征方法，探究了两种催化剂性能不同的原因，主要得到了以下结论：1。钨掺杂使得锰铈催化剂在保持高活性的同时降低了N2O的生成量，并提高了N2的选择性；2。锰铈催化剂生成N2O的机理比较复杂，其中Eley-Rideal 机理和Langmuir-Hinshelwood 机理的共同作用占主导地位，但NH3的氧化反应持续生成的N2O在总量中也不能被忽略；3。钨的掺杂使催化剂表面酸位点增多增强，增加了催化剂吸附酸性NOx气体的难度，抑制了NSCR反应，导致Mn-Ce-W催化剂的N2O生成量减少和N2选择性升高。78106

毕业论文关键词氮氧化物氨选择性催化还原 Mn-Ce-W催化剂尾气脱硝均匀沉淀法

毕业设计说明书外文摘要

Title An study of the influence of tungsten doping on manganese-cerium oxide catalyst for the selective catalytic reduction of NOx with NH3

Abstract A series of Mn-Ce catalysts and Mn-Ce-W catalysts were synthesized by homogeneous precipitation method in this paper。 NH3-SCR activity test were carried out to filter the best catalyst of the Mn-Ce catalysts group and Mn-Ce-W catalysts group: Mn3CeOx and Mn3CeW0。3Ox。 Analyzed the activity of Mn3CeW0。3Ox under different circumstances by adjusting the velocity and water content。 After activity tests, XRD, TPD, separate oxidation reaction, transient reaction and in situ DRIFT were used to search the reason of the phenomenons showed up by the dosing of tungsten。 By discussing those characterizations, follow conclusions were drew。 1。 By the dosing of tungsten, the production of N2O is decreased and the N2 selectivity is increased, meanwhile the activity of catalysts is still at a considerable level。 2。 N2O formation mechanism of manganese cerium catalyst is relatively complex, the synergistic effect of Eley-rideal mechanism and Langmuir-Hinshelwood mechanism was dominant, but NH3 oxidation producing N2O in constant also cannot be ignored in total。 3。 The increase of acid sites on the catalyst surface was enhanced by the doping of tungsten。, which increases the difficulty of adsorption of acid NOx gas, inhibits the NSCR reaction, and leads to the decrease of N2O production and the increase of N2 selectivity of Mn-Ce-W catalyst。

Keywords Nitrogen oxide NH3-SCR Mn-Ce-W catalysts Denitrification Homogeneous precipitation method

1 绪论 1

1。1 大气中NOx的污染现状 1

1。2 烟气脱硝技术简介 2

1。2。1 选择性催化还原法（SCR）脱硝技术简介 2

1。2。2 SCR脱硝机理 3

1。2。3 SCR催化剂的发展概况和存在的不足 3

1。3 烟气脱硝的发展前景及研究方向 4

1。4 本论文的主要工作 5

1。4。1论文的主要目的 5

1。4。2 论文主要内容 6

2 实验部分 7

2。1 实验仪器与所需药品 7

2。2 催化剂合成制备方法简介 8

2。3 催化剂制备铈基氧化物催化剂用于氨选择性催化还原氮氧化物:http://www.youerw.com/huaxue/lunwen_89928.html